The present invention relates generally to the spraying of plants and, more particularly, to a process of spraying row crops with an atomized, charged, aqueous solution and a nozzle for practicing same.
Although aqueous solutions, such as herbicides, may be applied to crops by several methods including crop dusting and hand application, by far the most common method of application is by an implement secured to a tractor. While relatively simple and adequate for effectively covering crops with a chemical, standard tractor-pulled implements often waste much of the chemical.
The majority of plant spraying involves either aqueous solutions or suspensions in water. A major shortcoming of this method of application is that a substantial portion of the sprayed product is wasted when it lands on the ground or is carried away by the wind.
Not only is the loss of such chemicals costly in a monetary sense, the excess chemical that must be applied to insure adequate crop coverage can often have a devastating impact on the environment. When large amounts of chemicals are applied to crops, the harmful repercussions are felt most quickly by beneficial insects and nearby wildlife. More importantly, heavy application of chemicals sometimes leads to detectable amounts of such chemicals in human drinking water. Since many such chemicals are, by their very nature, highly toxic a decrease in the amount of such chemicals used on crops through more precise application of the chemicals is a highly desirable goal both for the person applying the chemical as well as for the environment as a whole.
Electrostatic sprayers have been used in orchards to spray fruit trees with chemicals such as herbicides and fertilizers. These sprayers impart an electrical charge upon the chemical causing the chemical to be attracted to the plant being sprayed. With a greater percentage of the chemical sticking to the plant, less chemical is used and less is wasted. A problem with this technique is that the charging means imparts a disproportionately greater charge on droplets of chemical passing nearest the charging means and a disproportionately smaller or lack of charge on the droplets of chemical passing furthest from the charging means. Consequently, some droplets are given an unnecessarily strong charge while others are given no charge at all.
Another problem with the electrostatic spraying technique is that an air stream great enough to atomize the chemical propels the chemical so quickly that the resulting mist will often damage crops close to the air/chemical outlet. This potential crop damage prevents the technique from being applied to row crop spraying which entails placing the air/chemical outlets close to the crops.
The difficulties encountered in the prior art discussed hereinabove are substantially eliminated by the present invention.